This Stage I Slash Cut Performance Kit will increase the power and performance of the Hammer™. It includes a K&N air filter, vented air box cover, and a slash cut chrome exhaust pipe. It also includes EFI recalibration. Dealer installation is recommended. *Rated for off-road use only. A Hammer™ Stage III Performance Kit (# 2875302 – sold separately) can also be added to this Stage I Kit to provide the ultimate performance.